基于超声TOFD技术的管道焊缝在役检查方案研究

Study on the Program for Pipeline Weld In-service Inspection Based on the Ultrasonic TOFD Technique

为增强“华龙一号”核电机组主蒸汽管道焊缝在役阶段缺陷定量的准确性,利用便携式自动超声TOFD检测系统对52mm厚低合金钢产品环焊缝开展检测试验,结果表明,超声TOFD技术可以较好地适用于厚壁焊接结构的检测,具有较高的检测灵敏度。基于对超声TOFD技术近表面盲区问题的分析讨论,提出了采用超声TOFD技术与常规脉冲反射技术相结合的方案对“华龙一号”核电厂主蒸汽管道焊缝进行自动化超声检查,以满足焊缝缺陷精确定量和结构完整性评价需要。

In order to enhancethe sizing accuracy for defect inspected of the main steam pipeline weld of the HPR1000 during the in-service stage,the portable automatic ultrasonic TOFD testing system is applied to inspect the circumferential weld of the low alloy steel factory product with thickness of 52 mm.The inspection results show that the ultrasonic TOFD technique can be well adapted to the detection of thick-walled welded structures,and has a high sensitivity.By analyzing the problem of the near-surface dead zone with the ultrasonic TOFD technique,the automatic in-service inspection strategy for the welds of main steam pipelines'welds in HPR1000 nuclear power station is proposed,which is combined with the ultrasonic TOFD technique and the conventional pulse reflection technique,so as to achieve the purpose of accurate sizing and characterization of defects,and integrity evaluation of the weld structure.